/*
* Conditions Of Use 
* 
* This software was developed by employees of the National Institute of
* Standards and Technology (NIST), an agency of the Federal Government.
* Pursuant to title 15 Untied States Code Section 105, works of NIST
* employees are not subject to copyright protection in the United States
* and are considered to be in the public domain.  As a result, a formal
* license is not needed to use the software.
* 
* This software is provided by NIST as a service and is expressly
* provided "AS IS."  NIST MAKES NO WARRANTY OF ANY KIND, EXPRESS, IMPLIED
* OR STATUTORY, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTY OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT
* AND DATA ACCURACY.  NIST does not warrant or make any representations
* regarding the use of the software or the results thereof, including but
* not limited to the correctness, accuracy, reliability or usefulness of
* the software.
* 
* Permission to use this software is contingent upon your acceptance
* of the terms of this agreement
*  
* .
* 
*/
package gov.nist.javax.sip.parser;

import gov.nist.javax.sip.header.*;
import gov.nist.core.*;
import java.text.ParseException;

/**
 * Parser for the challenge portion of the authentication header.
 *
 * @version 1.2 $Revision: 1.7 $ $Date: 2007/02/06 16:40:02 $
 * @since 1.1
 *
 * @author Olivier Deruelle    <br/>
 *
 * 
 */

public abstract class ChallengeParser extends HeaderParser {

	/**
	 * Constructor
	 * @param String challenge  message to parse to set
	 */
	protected ChallengeParser(String challenge) {
		super(challenge);
	}

	/**
	 * Constructor
	 * @param String challenge  message to parse to set
	 */
	protected ChallengeParser(Lexer lexer) {
		super(lexer);
	}

	/**
	 * Get the parameter of the challenge string
	 * @return NameValue containing the parameter
	 */
	protected void parseParameter(AuthenticationHeader header)
		throws ParseException {

		if (debug)
			dbg_enter("parseParameter");
		try {
			NameValue nv = this.nameValue('=');
			header.setParameter(nv);
		} finally {
			if (debug)
				dbg_leave("parseParameter");
		}

	}

	/**
	 * parser the String message.
	 * @param header - header structure to fill in.
	 * @throws ParseException if the message does not respect the spec.
	 */
	public void parse(AuthenticationHeader header) throws ParseException {

		// the Scheme:
		this.lexer.SPorHT();
		lexer.match(TokenTypes.ID);
		Token type = lexer.getNextToken();
		this.lexer.SPorHT();
		header.setScheme(type.getTokenValue());

		// The parameters:
		try {
			while (lexer.lookAhead(0) != '\n') {
				this.parseParameter(header);
				this.lexer.SPorHT();
				char la = lexer.lookAhead(0);
				if (la == '\n' || la == '\0')
					break;
				this.lexer.match(',');
				this.lexer.SPorHT();
			}
		} catch (ParseException ex) {
			throw ex;
		}
	}
}
